/*
 * Copyright (c) 1987, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getopt.c	8.2 (Berkeley) 4/2/94";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int opterr = 1,			/* if error message should be printed */
  optind = 1,			/* index into parent argv vector */
  optopt,			/* character checked for validity */
  optreset;			/* reset getopt */
char *optarg;			/* argument associated with option */

#define	BADCH	(int)'?'
#define	BADARG	(int)':'
#define	EMSG	""

/*
 * getopt --
 *      Parse argc/argv argument vector.
 */
int
getopt (nargc, nargv, ostr)
     int nargc;
     char *const *nargv;
     const char *ostr;
{
  extern char *__progname;
  static char *place = EMSG;	/* option letter processing */
  char *oli;			/* option letter list index */

  if (optreset || !*place)
    {				/* update scanning pointer */
      optreset = 0;
      if (optind >= nargc || *(place = nargv[optind]) != '-')
	{
	  place = EMSG;
	  return (EOF);
	}
      if (place[1] && *++place == '-')
	{			/* found "--" */
	  ++optind;
	  place = EMSG;
	  return (EOF);
	}
    }				/* option letter okay? */
  if ((optopt = (int) *place++) == (int) ':' ||
      !(oli = strchr (ostr, optopt)))
    {
      /*
       * if the user didn't specify '-' as an option,
       * assume it means EOF.
       */
      if (optopt == (int) '-')
	return (EOF);
      if (!*place)
	++optind;
      if (opterr && *ostr != ':')
	(void) fprintf (stderr,
			"%s: illegal option -- %c\n", __progname, optopt);
      return (BADCH);
    }
  if (*++oli != ':')
    {				/* don't need argument */
      optarg = NULL;
      if (!*place)
	++optind;
    }
  else
    {				/* need an argument */
      if (*place)		/* no white space */
	optarg = place;
      else if (nargc <= ++optind)
	{			/* no arg */
	  place = EMSG;
	  if (*ostr == ':')
	    return (BADARG);
	  if (opterr)
	    (void) fprintf (stderr,
			    "%s: option requires an argument -- %c\n",
			    __progname, optopt);
	  return (BADCH);
	}
      else			/* white space */
	optarg = nargv[optind];
      place = EMSG;
      ++optind;
    }
  return (optopt);		/* dump back option letter */
}
